assume cs:codesg
codesg segment

datasg segment
   db '1. display      '
   db '2. brows        '
   db '3. replace      '
   db '4. modify       '
datasg ends

stacksg segment
   dw 0, 0, 0, 0, 0, 0, 0, 0
stacksg ends

start:
   mov ax, datasg
   mov ds, ax
   mov ax, stacksg
   mov ss, ax
   mov sp, 10h

;  行
   mov bx, 0
   mov cx, 4
row:
   push cx
   mov si, 0
   mov cx, 4
col:
   mov al, [bx + si +3]
   and al, 11011111b
   mov [bx + si +3], al
   inc si
   loop col

   add bx, 10h
   pop cx
   loop row

   mov ax, 4C00H
   int 21H

codesg ends

end start
